1. Technical Field
The present invention relates generally to seat back adjustment mechanisms and more particularly to a seat back adjustment mechanism that enables a seat back to be locked in a plurality of forward fold-down positions.
2. Discussion
Vehicle markets such as mini-van and sport utility are extremely competitive and a focus for improvement by automobile manufacturers. Specifically, automobile manufacturers seek to improve the overall utility and comfort of the vehicles in these markets in pursuit of attracting and keeping customers. One important feature is a flexible vehicle interior. Flexibility, in this sense, refers to the interior""s ability to provide seating that may be modified to suit a particular customer""s needs. For example, a customer might desire the removal of a rear seat to provide increased cargo space, while maintaining a middle seat or seats for additional passengers. Additionally, a passenger might desire the seat back of a front or middle seat to fold down, providing a work space while travelling. As such, a passenger could place a laptop computer on the folded down seat back or use the folded down seat back as a small desk for writing or reading.
While providing flexibility, vehicle seats must also include features for maintaining an occupant""s comfort, such as the ability to recline a seat back to any one of a number of desired positions. A variety of seat-back recliner and fold-forward adjustment mechanisms are commonly known in the art. But, traditional fold-forward adjustment mechanisms simply release the seat back such that it may be folded forward to a position generally parallel to the seat. Further, traditional adjustment mechanisms only provide a single fold-forward position for the seat back and are not locked in that position. If such a seat back including conventional recliner or fold-forward adjustment mechanisms was placed in the fold-forward position to be used by a passenger as a work surface while travelling, a problem might arise as the vehicle comes to a stop. A flat folded-forward seat back would allow items on the work surface, e.g., a laptop computer or book, to slide and possibly fall from the seat back during braking and acceleration of the vehicle.
It is therefore desirable in the industry to provide a fold-forward adjustment mechanism for use with a seat back that enables an operator to lock the seat back in a desired forward position. As such, a seat back could be folded forward while providing sufficient angle to prevent an object, such as a laptop computer or book, from sliding forward during braking.
The present invention provides an adjustment mechanism that enables a seat back to be locked in a plurality of forward fold-down positions relative to a seat. Accordingly, a back surface of a seat back can be positioned parallel to the seat or locked at various acute angles relative to the seat.
The adjustment mechanism, according to the principles of the present invention, includes inner and outer plates rotatably supported by an arm. The arm includes a first portion having a plurality of pawl teeth for selectively engaging a locking member, which is slidably supported between the inner and outer plates for locking the inner and outer plates in a plurality of rotational positions relative to the arm. A cam plate is rotatably supported between the inner and outer plates and is biased by a biasing member toward engaging the locking member. The cam plate can be operated to relieve the locking member, enabling a seat back to be rotated forward relative to the arm. Once rotated to a desired position, the adjustment member of the present invention can lock the seat back in that position.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.